When a user activates and/or unlocks a mobile device using his or her voice, user authentication should be as secure as possible. However, strong, secure, and/or accurate authentication can require increased power consumption. Sophisticated noise reduction needed for secure and/or accurate authentication can cause the mobile device to exceed its power budget. This increased power consumption can conflict with the requirement for a mobile device to consume as little power as possible.
Furthermore, voice sensing detection might not achieve balance between clean and noisy sound environmental conditions. For example, voice sensing might trigger upon incorrectly detecting a spoken keyword under clean (or reduced noise) conditions (i.e., a false positive). In other situations, voice sensing might not trigger at all due to the inability to detect a spoken keyword under noisy (or increased noise) conditions (i.e., a false negative).
In addition, a mobile device might allow a user to define a spoken keyword to be used in subsequent authentications. However, the user-defined spoken keyword might not be strong enough to prevent false authentications.